Polymerization of ethylene

ABSTRACT

Polyethylene is formed by contacting ethylene with a novel iron or cobalt complex of a selected 1,4,7-triaza-3-oxa-1,4,6-heptatriene or 2,5,8-triaza-1,8-nonadiene, optionally in the presence of a cocatalyst such as an alkylaluminum compound. The polymers formed as useful for molding and in films.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.09/556,204, filed Apr. 24, 2000, now U.S. Pat. No. 6,458,979 B1, whichclaims the benefit under 35 U.S.C. §119(e) of U.S. ProvisionalApplication Ser. No. 60/131,552, filed Apr. 29, 1999, which isincorporated by reference herein as if fully set forth.

FIELD OF THE INVENTION

Iron and cobalt complexes of selected1,4,7-triaza-3-oxa-1,4,6-heptatrienes or 2,5,8-triaza-1,8-nonadienes arecatalysts for the polymerization of ethylene, optionally in the presenceof cocatalysts such as alkylaluminum compounds.

TECHNICAL BACKGROUND

Polyethylenes are very important items of commerce, large quantities ofvarious grades of these polymers being produced annually for a largenumber of uses, such as packaging films and moldings. There are manydifferent methods for making such polymers, including many usedcommercially, such as free radical polymerization to make low densitypolyethylene, and many so-called coordination catalysts such asZiegler-Natta-type and metallocene-type catalysts. Each of thesecatalyst systems has its advantages and disadvantages, including cost ofthe polymerization and the particular structure of the polyethyleneproduced. Due to the importance of polyethylenes, new catalyst systemswhich are economical and/or produce new types of polyethylenes areconstantly being sought.

U.S. Pat. No. 5,955,555, WO98/30612, WO98/38228, WO99/02472 andWO99/12981 (incorporated by reference herein for all purposes) describethe use of iron or cobalt complexes of 2,6-diacylpyridinebisimines or2,6-pyridinedicarboxaldehydebisimines as catalysts for thepolymerization of olefins, mostly of ethylene. These publicationsdescribe the preparation of polyethylenes ranging in molecular weightfrom low molecular weight alpha-olefins and other oligomers to highmolecular weight polyethylenes. No mention is made, however, of the useof ligands such as described herein.

R. Roy, et al., Transition Met. Chem. (Weinheim, Ger.), Vol. 9, p.152-155 (1984) describes cobalt complexes of certain aminodiimines. Nomention is made of ligands or metal complexes such as described herein.

SUMMARY OF THE INVENTION

This invention concerns a first process for the production ofpolyethylene, comprising the step of contacting, at a temperature ofabout −100° C. to about +200° C., a monomer component comprisingethylene, and an Fe or Co complex of a ligand of the formula

wherein:

R¹, R² and R³ are each independently hydrogen, hydrocarbyl, substitutedhydrocarbyl or a functional group, or R¹ and R² taken together may forma ring;

Ar¹ and Ar² are each independently aryl or substituted aryl;

R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ are each independentlyhydrogen, hydrocarbyl, substituted hydrocarbyl, or a functional group,provided that any two of R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰ and R¹¹ that arevicinal to one another may form a ring;

R¹⁴ is hydrogen, hydrocarbyl or substituted hydrocarbyl; and

Ar³ and Ar⁴ are each independently aryl or substituted aryl.

Also disclosed herein is a second process for the production ofpolyethylene, comprising the step of contacting, at a temperature ofabout −100° C. to about +200° C., a monomer component comprisingethylene, a compound of the formula

and:

(a) a first compound W, which is a neutral Lewis acid capable ofabstracting X⁻, an alkyl group or a hydride group from M to form WX⁻,(WR²⁰)⁻ or WH⁻, and which is also capable of transferring an alkyl groupor a hydride to M, provided that WX⁻ is a weakly coordinating anion; or

(b) a combination of second compound which is capable of transferring analkyl or hydride group to M and a third compound which is a neutralLewis acid which is capable of abstracting X⁻, a hydride or an alkylgroup from M to form a weakly coordinating anion;

wherein:

M is Fe or Co;

each X is an anion;

n is an integer so that the total number of negative charges on saidanion or anions is equal to the oxidation state of M;

R¹, R² and R³ are each independently hydrogen, hydrocarbyl, substitutedhydrocarbyl or a functional group, or R¹ and R² taken together may forma ring;

Ar¹ and Ar² are each independently aryl or substituted aryl;

R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ are each independentlyhydrogen, hydrocarbyl, substituted hydrocarbyl, or a functional group,provided that any two of R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰ and R¹¹ that arevicinal to one another may form a ring;

R¹⁴ is hydrogen, hydrocarbyl or substituted hydrocarbyl;

Ar³ and Ar⁴ are each independently aryl or substituted aryl; and

R²⁰ is alkyl.

This invention also concerns a third process for the production ofpolyethylene, comprising the step of contacting, at a temperature ofabout −100° C. to about +200° C., a monomer component comprisingethylene, and a compound of the formula

wherein:

M is Fe or Co;

R¹, R² and R³ are each independently hydrogen, hydrocarbyl, substitutedhydrocarbyl or a functional group, or R¹ and R² taken together may forma ring;

Ar¹ and Ar² are each independently aryl or substituted aryl;

R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ are each independentlyhydrogen, hydrocarbyl, substituted hydrocarbyl, or a functional group,provided that any two of R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰ and R¹¹ that arevicinal to one another may form a ring;

R¹⁴ is hydrogen, hydrocarbyl or substituted hydrocarbyl;

Ar³ and Ar⁴ are each independently aryl or substituted aryl;

Z¹ is hydride, alkyl or an anionic ligand into which ethylene caninsert;

Y is a neutral ligand capable of being displaced by ethylene, or avacant coordination site;

Q is a relatively non-coordinating anion;

P is a divalent polyethylene group containing one or more ethyleneunits; and

Z² is an end group.

Also disclosed herein is a compound of the formula

wherein:

R¹, R² and R³ are each independently hydrogen, hydrocarbyl, substitutedhydrocarbyl or a functional group, or R¹ and R² taken together may forma ring;

Ar¹ and Ar² are each independently aryl or substituted aryl;

R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ are each independentlyhydrogen, hydrocarbyl, substituted hydrocarbyl, or a functional group,provided that any two of R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰ and R¹¹ that arevicinal to one another may form a ring;

R¹⁴ is hydrogen, hydrocarbyl or substituted hydrocarbyl; and

Ar³ and Ar⁴ are each independently aryl or substituted aryl.

Another compound disclosed herein is a compound of the formula

wherein:

M is Fe or Co;

R¹, R² and R³ are each independently hydrogen, hydrocarbyl, substitutedhydrocarbyl or a functional group, or R¹ and R² taken together may forma ring;

Ar¹ and Ar² are each independently aryl or substituted aryl;

R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ are each independentlyhydrogen, hydrocarbyl, substituted hydrocarbyl, or a functional group,provided that any two of R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰ and R¹¹ that arevicinal to one another may form a ring;

R¹⁴ is hydrogen, hydrocarbyl or substituted hydrocarbyl;

Ar³ and Ar⁴ are each independently aryl or substituted aryl;

Z¹ is hydride or alkyl or any other anionic ligand into which ethylenecan insert;

Y is a neutral ligand capable of being displaced by ethylene, or avacant coordination site;

Q is a relatively non-coordinating anion;

P is a divalent polyethylene group containing one or more ethyleneunits; and

Z² is an end group.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A structure drawn such as (II), (IV) and (V) through (X) simply meansthat the ligand in the square bracket is coordinated to themetal-containing moiety, as indicated by the arrow. Nothing is impliedin these formulas about what atoms in the ligand are coordinated to themetal. Without wishing to be bound by any particular theory, it isbelieved that (I) and (III) are tridentate ligands in coordinating withFe or Co, and that coordination is effected through the nitrogen atomsshown in formulas (I) and (III).

Herein, certain terms are used. Some of them are:

A “hydrocarbyl group” is a univalent group containing only carbon andhydrogen. If not otherwise stated, it is preferred that hydrocarbylgroups herein contain 1 to about 30 carbon atoms.

By “substituted hydrocarbyl” herein is meant a hydrocarbyl group whichcontains one or more substituent groups which are inert under theprocess conditions to which the compound containing these groups issubjected. The substituent groups also do not substantially interferewith the process. If not otherwise stated, it is preferred thatsubstituted hydrocarbyl groups herein contain 1 to about 30 carbonatoms. Included in the meaning of “substituted” are heteroaromaticrings. Also included in such groups are those in which hydrogen has beencompletely replaced by another group or element, as in trifluoromethyl.

By “(inert) functional group” herein is meant a group other thanhydrocarbyl or substituted hydrocarbyl which is inert under the processconditions to which the compound containing the group is subjected. Thefunctional groups also do not substantially interfere with (impede) anyprocess described herein that the compound in which they are present maytake part in. Examples of functional groups include, but are not limitedto, halo (fluoro, chloro, bromo and iodo), ether such as —OR¹⁸ whereinR¹⁸ is hydrocarbyl or substituted hydrocarbyl, nitro, silyl, tertiaryamino, thioether and ester. In cases in which the functional group maybe near a cobalt or iron atom, the functional group should preferablynot coordinate to the metal atom more strongly than the usualcoordinating groups, that is they should preferably not displace thedesired coordinating group.

By an “alkyl aluminum compound” is meant a compound in which at leastone alkyl group is bound to an aluminum atom. Other groups such asalkoxide, hydride, and halogen may also be bound to aluminum atoms inthe compound.

By “neutral Lewis base” is meant a compound, which is not an ion, whichcan act as a Lewis base. Examples of such compounds include ethers,amines, sulfides, and organic nitrites.

By “cationic Lewis acid” is meant a cation which can act as a Lewisacid. Examples of such cations are sodium and silver cations.

By “relatively noncoordinating anions” (or “weakly coordinating anions”)is meant those anions as are generally referred to in the art in thismanner, and the coordinating ability of such anions is known and hasbeen discussed in the literature, see for instance W. Beck., et al.,Chem. Rev., vol. 88 p. 1405-1421 (1988), and S. H. Strauss, Chem. Rev.,vol. 93, p. 927-942 (1993), both of which are hereby included byreference. Among such anions are those formed from the aluminumcompounds in the immediately preceding paragraph and X⁻, including R⁹₃AlX⁻, R⁹ ₂AlClX⁻, R⁹AlCl₂X⁻, and “R⁹AlOX⁻”, wherein R⁹ is alkyl. Otheruseful noncoordinating anions includeBAF⁻{BAF=tetrakis[3,5-bis(trifluoromethyl)phenyl]borate}, SbF₆ ³¹, PF₆⁻, and BF₄ ⁻, trifluoromethanesulfonate, p-toluenesulfonate,(R_(f)SO₂)₂N⁻, and (C₆F₅)₄B⁻.

By an “empty coordination site” is meant a potential coordination sitethat is not occupied by a ligand. Thus if an ethylene molecule is in theproximity of the empty coordination site, the ethylene molecule maycoordinate to the metal atom.

“Aryl” herein also includes heterocyclic rings.

By a “ligand that may add to ethylene” is meant a ligand coordinated toa metal atom into which an ethylene molecule (or a coordinated ethylenemolecule) may insert to start or continue a polymerization. Forinstance, this may take the form of the reaction (wherein L is aligand):

By a “1,4,7-triaza-3-oxa-1,4,6-heptatriene” herein is meant a compoundhaving the backbone (with appropriate groups attached of

while by a “2,5,8-triaza-1,8-nonadiene” is meant a compound with thebackbone (with appropriate groups attached) of

By an “end group” such as Z² is meant a group bound to the metal atominto which the first ethylene molecule of the polymer being formedinserted. Typically this will be Z¹.

By “═” in formulas such as (VI), (VII), (IX) and (X) is meant anethylene molecule.

By “polyethylene” is, in its broadest sense, meant a polymer basedpredominantly on ethylene, that is, a polymer in which at least 50 molepercent of the repeat units are dervied from ethylene in thepolymerization process. Preferably, the polyethylenes referred to hereinhave at least 70 mole percent, and more preferably at least 80 molepercent, of the repeat units are derived from ethylene in thepolymerization process. By a “homopolyethylene” herein is meant apolymer in which substantially all of the repeat units are derived fromethylene in the polymerization process. “Derived from ethylene” includesany comonomers generated in situ (either simultaneously with or inseries with the actual polymerization) from ethylene such as, forexample, those ethylene oligomers formed by the ethylene oligomerizationcatalyst. Homopolyethylenes are preferred herein.

Iron is a preferred transition metal in all coordination compounds of(I) and (III) (and in processes in which they are used) herein.

Preferred groups in compounds (I) and (III) and their correspondingmetal complexes are:

R¹ and R² are each independently hydrogen or alkyl containing 1 to 4carbon atoms, more preferably both R¹ and R² are hydrogen or methyl;and/or

R¹ and R² taken together form a ring, more preferably a carbocyclicring, and especially preferably R¹ and R² taken together are

R³ is aryl, substituted aryl or alkyl, more preferably aryl, substitutedaryl or alkyl containing 1 to 4 carbon atoms, especially preferablyphenyl, t-butyl or methyl; and/or

Ar¹ and Ar² are 2-substituted (with no substitution in the 6 position)or 2,6-disubstituted phenyl with substitution optional at any other ringposition; and more preferably the substituents in the 2 and 6 (whenpresent) positions are alkyl containing 1 to 4 carbon atoms or hydrogen;and/or

R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ are each hydrogen; and/or

R¹² and R¹³ are hydrogen; and/or

R¹⁴ is hydrogen or hydrocarbyl, more preferably hydrogen or alkyl,especially preferably methyl or hydrogen, and highly preferablyhydrogen; and/or

Ar³ and Ar⁴ are 2-substituted (with no substitution in the 6 position)or 2,6-disubstituted phenyl with substitution optional at any other ringposition; and more preferably the substituents in the 2 and 6 (whenpresent) positions are alkyl containing 1 to 4 carbon atoms or hydrogen;and/or

Ar³ and Ar⁴ are 9-anthracenyl; and/or

Ar³ and Ar⁴ are the same.

In compounds in which it occurs, it is preferred that X is halo(especially chloride or bromide), carboxylate such as acetate, citrate,cyclohexane butyrate, 2-ethylhexanoate, stearate and oxalate,acetylacetonate, benzoylacetonate, hexafluoroacetylacetonate, hydroxide,2,2,6,6-tetramethyl-3,5-heptanedionate, p-toluenesulfonate, ethoxide,i-propoxide, trifluoroacetylacetonate, and tetrafluoroborate. Especiallypreferred anions X are halide, carboxylate and acetylacetonate.

The iron and cobalt in the complexes may be in the +2 or +3 oxidationstate, and +2 is preferred.

Ar¹, Ar², Ar³, and Ar⁴ may also each independently be aryl, substitutedaryl, hydrocarbyl or substituted hydrocarbyl provided that in thehydrocarbyl or substituted hydrocarbyl groups the carbon atom bound tothe imino nitrogen is bound to at least two other carbon atoms. It ispreferred that Ar¹, Ar², Ar³, and Ar⁴ are each independently aryl orsubstituted aryl.

Specific preferred compounds for (I) and (III), and their correspondingFe and Co complexes, are:

Included within the meaning of compounds (VII) and (X) are agosticstructures in which the ethylene is replaced as a ligand by coordinationto —PZ² to form an agostic “bidentate” ligand.

In the second polymerization process described herein an iron or cobaltcomplex (II) or (IV) is contacted with ethylene and a neutral Lewis acidW capable of abstracting X−, hydride or alkyl from (II) or (IV) to forma weakly coordinating anion, and must alkylate or be capable of adding ahydride ion to the metal atom, or an additional alkylating agent or anagent capable of adding a hydride anion to the metal atom must bepresent. The neutral Lewis acid is originally uncharged (i.e., notionic). Suitable neutral Lewis acids include SbF₅, Ar₃B (wherein Ar isaryl), and BF₃. In those instances in which (II) or (IV) (and similarcatalysts which require the presence of a neutral Lewis acid), does notcontain an alkyl or hydride group already bonded to the metal atom, theneutral Lewis acid or a cationic Lewis or Bronsted acid also alkylatesor adds a hydride to the metal or a separate alkylating or hydridingagent is present, i.e., causes an alkyl,group or hydride to becomebonded to the metal atom.

It is preferred that R²⁰contains 1 to 4 carbon atoms, and more preferredthat R²⁰ is methyl or ethyl.

For instance, alkyl aluminum compounds (see next paragraph) may alkylate(II). However, not all alkyl aluminum compounds may be strong enoughLewis acids to abstract X− or an alkyl group from the metal atom. Inthat case a separate Lewis acid strong enough to do the abstraction mustbe present.

A preferred neutral Lewis acid, which can alkylate the metal, is aselected alkyl aluminum compound, such as R¹⁹ ₃Al, R¹⁹AlCl₂, R¹⁹ ₂AlCl,and “R¹⁹AlO” (alkylaluminoxanes), wherein R¹⁹ is alkyl containing 1 to25 carbon atoms, preferably 1 to 4 carbon atoms. Suitable alkyl aluminumcompounds include methylaluminoxane (which is an oligomer with thegeneral formula [MeAlO]_(n)), optionally modified with minor amounts ofother alkyl groups, (C₂H₅)₂AlCl, C₂H₅AlCl₂, and [(CH₃)₂CHCH₂]₃Al.

Metal hydrides such as NaBH₄ may be used to bond hydride groups to themetal M.

The polymerization catalysts and catalyst systems described herein mayproduce polyethylene in a variety of molecular weights and molecularweight distributions. The molecular weights of these polymers may varyfrom compounds containing only a few ethylene molecules (e.g.,oligomers) to polymers having molecular weights in the hundreds ofthousands, and even higher. The molecular weight of the polymer producedin any particular polymerization process will depends on the processconditions used, and on the compound [such as (I) and (III)] which isused in the polymerization catalyst system. In one form of “chaintransfer” in the polymerization process it is believed that an olefinicgroup is formed on the end of the polymer chain (see Examples 23-44,wherein Mn is measured by ¹H NMR assuming all olefinic groups are endgroups). If the olefinic group is on the end of a linear polymer chainthat happens to be a relatively short polymer chain (say containing 4 toabout 30 carbon atoms) the product is sometimes termed a linear α-olefin(LAO). LAOs are important items of commerce, useful as monomers and aschemical intermediates for items such as detergents and lubricatingoils. For making LAOs it is preferred that in (I) and (III), and theirFe and Co complexes, that Ar¹ and Ar²are independently phenyl or2-substituted phenyl, or Ar³ and Ar⁴are independently phenyl or2-substituted phenyl, for example 2-methylphenyl or 2-i-propylphenyl.

Compounds such as (I) may be made by reacting an appropriate dicarbonylcompound with one mole of hydroxylamine to form the monooxime. Thisoxime containing a second carbonyl group is then reacted with anarylamine to form the imine-oxime. The anion of the oxime is then formedby reaction with a strong base, such as an alkali metal hydride,followed by reaction with an appropriate chloroimine to form (I). Thechloroimines are made by reaction of the appropriate amide with achlorinating agent such as PCl₅. These various reactions are illustratedherein in Examples 1-9.

(III) may be made by the reaction of the appropriate diethylenetriamine(or appropriate analog) with a carbonyl substituted aryl compound.

Complexes of (I) or (III) with Fe or Co may be made by methods known inthe art, see for instance previously incorporated U.S. Pat. No.5,955,555, wherein the preparation of Fe and Co complexes ofpyridinebisimines are described. Analogous methods may be used to makecomplexes of (I) and (III).

In all the polymerization processes herein, the temperature at which thepolymerization is carried out is about −100° C. to about +200° C.,preferably about 0° C. to about 150° C., more preferably about 25° C. toabout 100° C. The ethylene concentration at which the polymerization iscarried out is not critical, atmospheric pressure to about 275 MPa beinga suitable range for ethylene.

The polymerization processes herein may be run in the presence ofvarious liquids, particularly aprotic organic liquids. The catalystsystem, ethylene, and polyethylene may be soluble or insoluble in theseliquids, but obviously these liquids should not prevent thepolymerization from occurring. Suitable liquids include alkanes,cycloalkanes, selected halogenated hydrocarbons, selected aromatichalogenated hydrocarbons, and aromatic hydrocarbons. Hydrocarbons arethe preferred solvent. Specific useful solvents include hexane, heptane,toluene, benzene, chlorobenzene, methylene chloride,1,2,4-trichorobenzene, p-xylene, and cyclohexane.

The catalysts herein may be “heterogenized” by coating or otherwiseattaching them to solid supports, such as silica or alumina. Where anactive catalyst species is formed by reaction with a compound such as analkylaluminum compound, a support on which the alkylaluminum compound isfirst coated or otherwise attached is contacted with the iron or cobaltcompound precursor to form a catalyst system in which the active iron orcobalt catalyst is “attached” to the solid support. These supportedcatalysts may be used in polymerizations in organic liquids, asdescribed in the immediately preceding paragraph. They may also be usedin so-called gas phase polymerizations in which the ethylene beingpolymerized is added to the polymerization as a gas and no liquidsupporting phase is present.

The polymerization processes described herein may be run in any mannercommon for coordination olefin polymerization processes, such as batch,semi-batch, and continuous. Processes applicable generally toZiegler-Natta and metallocene-type polymerization catalysts may also beused in the present processes. The processes may be run in solution,slurry or gas phases.

It is believed that usually the homopolyethylene produced by the presentpolymerization processes are fairly linear polymers with littlebranching.

It is known that certain transition metal containing polymerizationcatalysts are especially useful in varying the branching in polyolefinsmade with them, see for instance U.S. Pat. Nos. 5,714,556, 5,880,241,WO98/30610 and WO98/30609 (all of which are incorporated by referenceherein for all purposes). It is also known that blends of distinctpolymers, that vary for instance in branching, molecular weight, and/ormolecular weight distribution, may have advantageous properties comparedto “single” polymers. For instance it is known that polymers with broador bimodal molecular weight distributions may be melt processed (beshaped) more easily than narrower molecular weight distributionpolymers. Similarly, thermoplastics such as crystalline polymers mayoften be toughened by blending with elastomeric polymers.

Therefore, methods of producing polymers which inherently producepolymer blends are useful especially if a later separate (and expensive)polymer mixing step can be avoided. However in such polymerizations oneshould be aware that two different catalysts may interfere with oneanother, or interact in such a way as to give a single polymer.

In such a process the catalysts disclosed herein can be termed the firstactive polymerization catalyst. Monomers useful with these catalysts arethose described (and also preferred) above.

A second active polymerization catalyst (and optionally one or moreothers) is used in conjunction with the first active polymerizationcatalyst. The second active polymerization catalyst may be another latetransition metal catalyst, for example as described in previouslyincorporated WO98/30610, WO98/30609, U.S. Pat. Nos. 5,714,556, 5,880,241and U.S. Pat. No. 5,955,555.

Other useful types of catalysts may also be used for the second activepolymerization catalyst. For instance so-called Ziegler-Natta and/ormetallocene-type catalysts may also be used. These types of catalystsare well known in the polyolefin field, see for instance Angew. Chem.,Int. Ed. Engl., vol. 34, p. 1143-1170 (1995), EP-A-0416815 and U.S. Pat.No. 5,198,401 for information about metallocene-type catalysts, and J.Boor Jr., Ziegler-Natta Catalysts and Polymerizations, Academic Press,New York, 1979 for information about Ziegler-Natta-type catalysts, allof which are hereby included by reference. Many of the usefulpolymerization conditions for all of these types of catalysts and thefirst active polymerization catalysts coincide, so conditions for thepolymerizations with first and second active polymerization catalystsare easily accessible. Oftentimes the “co-catalyst” or “activator” isneeded for metallocene or Ziegler-Natta-type polymerizations. In manyinstances the same compound, such as an alkylaluminum compound, may beused as an “activator” for some or all of these various polymerizationcatalysts.

Suitable catalysts for the second polymerization catalyst also includemetallocene-type catalysts, as described in U.S. Pat. No. 5,324,800 andEP-0129368; particularly advantageous are bridged bis-indenylmetallocenes, for instance as described in U.S. Pat. No. 5,145,819 andEP-A-0485823. Another class of suitable catalysts comprises thewell-known constrained geometry catalysts, as described in EP-A-0416815,EP-A-0420436, EP-A-0671404, EP-A-0643066 and WO91/04257. Finally, theclass of transition metal complexes described in WO96/13529 can be used.All of the above-mentioned publications are hereby included by referenceherein.

In one preferred process described herein the first olefin(s) [themonomer(s), usually ethylene, polymerized by the first activepolymerization catalyst] and second olefin(s) [the monomer(s)polymerized by the second active polymerization catalyst] are identical,and preferred olefins in such a process are the same as describedimmediately above. The first and/or second olefins may also be a singleolefin or a mixture of olefins to make a copolymer. Again it ispreferred that they be identical particularly in a process in whichpolymerization by the first and second active polymerization catalystsmake polymer simultaneously.

In some processes herein the first active polymerization catalyst maypolymerize a monomer that may not be polymerized by said second activepolymerization catalyst, and/or vice versa. In that instance twochemically distinct polymers may be produced. In another scenario twomonomers would be present, with one polymerization catalyst producing acopolymer, and the other polymerization catalyst producing ahomopolymer, or two copolymers may be produced which vary in the molarproportion or repeat units from the various monomers. Other analogouscombinations will be evident to the artisan.

In another variation of this process one of the polymerization catalystsmakes an oligomer of an olefin, preferably ethylene, which oligomer hasthe formula R⁷⁰CH═CH₂, wherein R⁷⁰ is n-alkyl, preferably with an evennumber of carbon atoms. The other polymerization catalyst in the processthen (co)polymerizes this olefin, either by itself or preferably with atleast one other olefin, preferably ethylene, to form a branchedpolyolefin. Preparation of the oligomer (which is sometimes called anα-olefin) by a second active polymerization-type of catalyst can befound in previously incorporated U.S. Pat. No. 5,880,241, and WO99/02472(also incorporated by reference herein for all purposes).

Likewise, conditions for such polymerizations, using catalysts of thesecond active polymerization type, will also be found in the appropriateabove mentioned references.

Two chemically different active polymerization catalysts are used inthis polymerization process. The first active polymerization catalyst isdescribed in detail above. The second active polymerization catalyst mayalso meet the limitations of the first active polymerization catalyst,but must be chemically distinct. For instance, it may have a differenttransition metal present, and/or utilize a different type of ligandand/or the same type of ligand which differs in structure between thefirst and second active polymerization catalysts. In one preferredprocess, the ligand type and the metal are the same, but the ligandsdiffer in their substituents.

Included within the definition of two active polymerization catalystsare systems in which a single polymerization catalyst is added togetherwith another ligand, preferably the same type of ligand, which candisplace the original ligand coordinated to the metal of the originalactive polymerization catalyst, to produce in situ two differentpolymerization catalysts.

The molar ratio of the first active polymerization catalyst to thesecond active polymerization catalyst used will depend on the ratio ofpolymer from each catalyst desired, and the relative rate ofpolymerization of each catalyst under the process conditions. Forinstance, if one wanted to prepare a “toughened” thermoplasticpolyethylene that contained 80% crystalline polyethylene and 20% rubberypolyethylene, and the rates of polymerization of the two catalysts wereequal, then one would use a 4:1 molar ratio of the catalyst that gavecrystalline polyethylene to the catalyst that gave rubbery polyethylene.More than two active polymerization catalysts may also be used if thedesired product is to contain more than two different types of polymer.

The polymers made by the first active polymerization catalyst and thesecond active polymerization catalyst may be made in sequence, i.e., apolymerization with one (either first or second) of the catalystsfollowed by a polymerization with the other catalyst, as by using twopolymerization vessels in series. However it is preferred to carry outthe polymerization using the first and second active polymerizationcatalysts in the same vessel(s), i.e., simultaneously. This is possiblebecause in most instances the first and second active polymerizationcatalysts are compatible with each other, and they produce theirdistinctive polymers in the other catalyst's presence. Any of theprocesses applicable to the individual catalysts may be used in thispolymerization process with 2 or more catalysts, i.e., gas phase, liquidphase, continuous, batch etc.

The polymers produced by this “mixed catalyst” process may vary inmolecular weight and/or molecular weight distribution and/or meltingpoint and/or level of crystallinity, and/or glass transition temperatureand/or other factors. For copolymers the polymers may differ in ratiosof comonomers if the different polymerization catalysts polymerize themonomers present at different relative rates. The polymers produced areuseful as molding and extrusion resins and in films as for packaging.They may have advantages such as improved melt processing, toughness andimproved low temperature properties.

Hydrogen may be used to lower the molecular weight of polyethyleneproduced in the first, second or third processes, or any other processesmentioned above in which the present transition metal complexes areused. It is preferred that the amount of hydrogen present be about 0.01to about 50 mole percent of the ethylene present, preferably about 1 toabout 20 mole percent. The relative concentrations of ethylene andhydrogen may be regulated by their partial pressures.

Included herein within the definitions of all the polymerizationprocesses are mixtures of starting materials that lead to the formationin situ of the transition metal compounds specified in all of thepolymerization processes.

In the first, second and third polymerization process, and otherpolymerization processes herein one or more olefins of the formulaR¹⁵CH═CH₂ may be homopolymerized or copolymerized with each and/or withethylene using the iron and cobalt complex of (I) and (III), asdescribed herein. Similar (to ethylene polymerization) processconditions may be used to carry out these polymerizations.

The polymers produced by the present processes are useful as moldingresins, for films and other uses. End use areas include industrial andconsumer parts and packaging.

In the Examples, the following abbreviations are used:

Ar—aryl

Et—ethyl

GPC—gel permeation chromatography

Me—methyl

MI—melt index

PE—polyethylene

Ph—phenyl

RT—room temperature

TCB—1,2,4-trichlorobenzene

THF—tetrahydrofuran

TO—turnovers

EXAMPLE 1 ArN═C(Me)—C(Me)═N—OH (Ar=2,6-C₆H₃-(i-Pr)₂)

2,3-Butanedione monooxime (20.753 g, 0.205 mmol) and2,6-diisopropylaniline (47.31 g, 0.267 mol, 1.30 equiv.) were dissolvedin ˜100 mL of methanol along with 10 drops of formic acid. The reactionmixture was stirred several days. A white precipitate formed, which wascollected on a frit and then dissolved in methylene chloride; theresulting solution was stirred overnight over sodium sulfate. Themixture was then filtered through a frit with Celite®, the solvent wasremoved and the product was dried in vacuo to yield 30.71 g of a whitepowder. An additional 11.57 g of product was obtained by concentratingthe remaining methanol solution (79.1% total yield): ¹H NMR (CDCl₃, 500MHz) δ 8.32 (s, 1, OH), 7.07 (d, 2, H_(aryl)), 7.00 (t, 1, H_(aryl)),2.54 (septet, 2, CHMe₂), 2.20 and 1.81 (s, 3 each, N═C(Me)—C′ (Me)═N),1.06 and 1.08 (d, 6 each, CHMeMe′); ¹³C NMR (CDCl₃, 125 MHz) δ 163.9 and158.6 (N═C—C′═N), 145.7 (Ar: C_(ipso)), 135.3, 123.6 and 122.9 (Ar:C_(o,m,p)), 28.2 (CHMe₂), 23.0 and 22.7 (CHMeMe′), 16.3 and 9.3(N═C(Me)—C′ (Me)═N). The structure of this compound was confirmed byX-ray crystal structure analysis.

EXAMPLE 2 ArN═C(Me)—C(Me)═N—ONa (Ar=2,6-C₆H₃-(i-Pr)₂)

In a nitrogen-filled drybox, ArN═C(Me)—C(Me)═N—OH (Ar=2,6-C₆H₃-(i-Pr)₂(3.652 g, 14.03 mmol) was dissolved in ˜100 mL of THF. Sodium hydride(0.660 g, 27.5 mmol, 1.96 equiv) was slowly added to the flask and thereaction mixture was stirred for four days. The reaction mixture wasthen filtered through a frit with Celite® and the THF was removed invacuo to yield 3.43 g of yellow powder (87% yield): ¹H NMR (THF-d₈, 300MHz) δ 7.03 (d, 2, H_(aryl)), 6.89 (t, 1, H_(aryl)) 2.73 (septet, 2,CHMe₂), 2.17 and 1.91 (s, 3, each, N═C(Me)—C′ (Me)═N), 1.12 and 1.08 (d,6 each, CHMeMe′). (Note: Reaction times for this deprotonation arevariable. Prior to work-up, the ¹H NMR spectrum of a small sample of thereaction mixture was typically checked for the —OH resonance todetermine if the reaction was complete.)

EXAMPLE 3

Acenaphthenequinone (10.00 g, 54.89 mmol) and hydroxylaminehydrochloride (3.814 g, 54.89 mmol) were dissolved in a mixture of 50 mLof ethanol, 50 mL of dichloromethane, and 50 mL of pyridine. Thereaction mixture was stirred for several days before adding water andextracting the product with dichloromethane. The dichloromethanesolution was stirred overnight over sodium sulfate and then the mixturewas filtered through a frit with Celite®. The solvent was removed andthe resulting pale orange powder (9.871 g, 91.2%) was dried in vacuo: ¹HNMR (N,N-dimethylformamide-d₇, 500 MHz) δ 11.85 (br s, 1, N—OH), 8.72(d, 1, H_(aryl)), 8.69 (d, 1, H_(aryl)), 8.55 (d, 1, H_(aryl)), 8.40 (d,1, H_(aryl)), 8.24 (t, 1 H_(aryl)), 8.18 (t, 1, H_(aryl))

EXAMPLE 4

Phenanthrenequinone (2.00 g, 9.61 mmol) and hydroxylamine hydrochloride(0.6675 g, 9.61 mmol) were dissolved in a mixture of 10 mL of ethanol,10 mL of dichloromethane, and 10 mL of pyridine. The reaction mixturewas stirred for several days before adding water and extracting theproduct with dichloromethane. The dichloromethane solution was stirredovernight over sodium sulfate and then filtered through a frit withCelite®. The solvent was removed and the resulting orange powder (1.83g, 85.3%) was dried in vacuo: ¹H NMR (CDCl₃, 500 MHz) δ 8.34 (d, 1,H_(aryl)), 8.28 (d, 1, H_(aryl)), 8.10 (d, 1, H_(aryl)), 8.03 (d, 1,H_(aryl)), 7.72 (t, 1, H_(aryl)) 7.47 (t, 1, H_(aryl)), 7.46 (t, 1,H_(aryl)) 7.40 (t, 1, H_(aryl)) ¹³C NMR (CDCl₃, 125 MHz) δ 182.1 (C═O),143.9 (C═N), 137.4-123.1 (C_(aryl)).

EXAMPLES 5-9

The procedures for the syntheses of ligands (Ia-e) and (IIa) are givenin the examples below.

Synthesis of Amides. The amide precursors to the chloroimines wereeither obtained from commercial sources [e.g., MeC(O)NHAr(Ar=2,6-C₆H₃—Me₂) and t-BuC(O)NHAr (Ar=2-C₆H₄—Me)] or synthesizedaccording to the following general procedure [e.g., PhC(O)NHAr(Ar=2,6-C₆H₃-(i-Pr)₂, PhC(O)NHAr (Ar=2,6-C₆H₃—Me₂), MeC(O)NHAr(Ar=2,6-C₆H₃-(i-Pr)₂]: A dry Schlenk flask was attached to a Schlenkline, evacuated, and back-filled with argon. Dry solvent (˜300 mL ofeither hexanes or toluene), the aniline (˜113 mmol), and 1.3 equiv oftriethylamine were placed in the Schlenk flask. A dry addition funnelwas attached to the Schlenk flask and a solution of the acid halide (1.1equiv) in the dry solvent (˜50 mL of either hexanes or toluene) wasplaced in the addition funnel. The flask was cooled to 0° C. and theacid halide solution was slowly added to the flask. After the additionwas complete, the reaction mixture was allowed to warm to roomtemperature and then stirred overnight. A precipitate formed and, ifnecessary, additional solvent was added to enable stirring. Next, waterwas added to the flask and the resulting mixture was stirred well. Theremaining precipitate was collected on a frit and washed with water andthen petroleum ether. The solid was dissolved in THF and the resultingsolution was stirred overnight over sodium sulfate. The mixture wasfiltered through a frit with Celite®, the solvent was evaporated, andthe white powder was dried in vacuo. ¹H NMR spectra of the resultingamides are reported below.

PhC(O)NHAr (Ar=2,6-C₆H₃-(i-Pr)₂. Synthesized from PhC(O)Cl and ArNH₂: ¹HNMR (THF-d₈, 500 MHz) δ 9.02 (br s, 1, NH), 7.97 (d, 2, C_(Ph)), 7.50(t, 1, C_(Ph)), 7.41 (t, 2, C_(Ph)) 7.30 (t, 1, C_(aryl)), 7.20 (d, 2,C_(aryl)), 3.22 (septet, 2, CHMe₂), 1.21 (d, 12, CHMe₂).

PhC(O)NHAr (Ar=2,6-C₆H₃—Me₂). Synthesized from PhC(O)Cl and ArNH₂: ¹HNMR (CDCl₃, 500 MHz) δ 7.93 (d, 2, C_(Ph)), 7.61 (br s, 1, NH), 7.58 (t,1, C_(Ph)), 7.51 (t, 2, C_(Ph)) 7.15 (m, 3, H_(aryl)), 2.29 (s, 6, Me)

MeC(O)NHAr (Ar=2,6-C₆H₃-(i-Pr)₂. Synthesized from MeC(O)Cl and ArNH₂: ¹HNMR (CDCl₃, 500 MHz) Two isomers are present. Major isomer: δ 7.17 (t,1, C_(aryl)), 7.15 (br s, 1, NH), 7.03 (d, 2, H_(aryl)), 2.92 (septet,2, CHMe₂), 2.12 (s, 3, Me), 1.16 (d, 12, CHMe₂); Minor isomer: δ 7.48(s, 1, NH), 7.22 (t, 1, H_(aryl)), 7.09 (d, 2, H_(aryl)), 3.01 (septet,2, CHMe₂), 1.68 (s, 3, Me), 1.22 and 1.14 (d, 6 each, CHMeMe′).

Synthesis of Chloroimines. The chloroimines [ArN═C(Cl) (Ph)(Ar=2,6-C₆H₃-(i-Pr)₂), ArN═C(Cl) (Ph) (Ar=2,6-C₆H₃—Me₂), ArN═C(Cl) (Me)(Ar=2,6-C₆H₃-(i-Pr)₂), ArN═C(Cl) (Me) (Ar=2,6-C₆H₃—Me₂), and ArN═C(Cl)(t-Bu) (Ar=2-C₆H₄—Me) were synthesized according to the followinggeneral procedure: In a nitrogen-filled drybox, the amide (˜90 mmol) wasplaced in a Schlenk flask and suspended in ˜100 mL of dry toluene. PCl₅(1.1 equiv) was added to the toluene suspension, and then the Schlenkflask was capped with a septum and removed from the drybox. In a fumehood, the septum was removed from the flask and the flask was quicklyconnected to a reflux condenser attached to a nitrogen source and aNaOH(aq) trap. The reaction mixture was refluxed until HCl evolution hadceased (typically ˜1 day). The reaction mixture was allowed to cool toRT. The reflux condenser was removed and the flask was quickly cappedwith a septum and attached to a Schlenk line. A cannula-filter was usedto filter the solution and transfer it into another Schlenk flask. Thesolvent was evaporated to yield the chloroimine as either a powder or anoil, and the evacuated flask was then brought back into the drybox. Inthe drybox, further purification of the product was sometimes carriedout by dissolving the chloroimine in pentane and filtering the solutionthrough a frit with Celite® and removing the solvent in vacuo. ¹H NMRspectra of the chloroimines were obtained and are reported below.Absence of phosphorus-containing by-products was confirmed by ³¹P NMRspectroscopy.

ArN═C(Cl) (Ph) (Ar=2,6-C₆H₃-(i-Pr)₂). Synthesized from PhC(O)NHAr: ¹HNMR (CDCl₃, 500 MHz) δ 8.28 (d, 2, C_(Ph)), 7.62 (t, 1, C_(Ph)), 7.56(t, 2, C_(Ph)), 7.25 (m, 3, C_(aryl)), 2.90 (septet, 2, CHMe₂), 1.30 and1.23 (CHMeMe′).

ArN═C(Cl) (Ph) (Ar=2,6-C₆H₃—Me₂). Synthesized from PhC(O)NHAr: ¹H NMR(CDCl₃, 500 MHz) δ 8.27 (d, 2, C_(Ph)), 7.62 (t, 1, C_(Ph)), 7.55 (t, 2,C_(Ph)), 7.15 (d, 2, C_(aryl)), 7.09 (t, 1, C_(aryl)), 2.18 (s, 6, Me).

ArN═C(Cl) (Me) (Ar=2,6-C₆H₃-(i-Pr) ₂). Synthesized from MeC(O)NHAr: ¹HNMR (C₆D₆, 500 MHz) δ 7.23 (m, 3, H_(aryl)), 3.05 (septet, 2, CHMe₂),2.28 (s, 3, Me), 1.5−1.2 (br m, 12, CHMeMe′).

ArN═C(Cl) (Me) (Ar=2,6-C₆H₃—Me₂). Synthesized from MeC(O)NHAr: ¹H NMR(CDCl₃, 500 MHz) δ 7.13 (d, 2, H_(aryl)) 7.07 (t, 1, H_(aryl)), 2.70 (s,3, Me), 2.19 (s, 6, Ar: Me).

ArN═C(Cl) (t-Bu) (Ar=2-C₆H₄—Me). Synthesized from t-BuC(O)NHAr: ¹H NMR(C₆D₆, 500 MHz) δ 7.17 (t, 1, H_(aryl)), 7.16 (d, 1, H_(aryl)), 7.05 (t,1, H_(aryl)), 6.87 (d, 1, H_(aryl)), 2.17 (s, 3, Me), 1.37 (s, 9, CMe₃).

EXAMPLE 5 Ligand (Ia)

In a nitrogen-filled drybox, ArN═C(Me)—C(Me)═N—ONa (Ar=2,6-C₆H₃-(i-Pr)₂) (0.891 g, 3.16 mmol) and ArN═C(Cl) (Ph) (Ar=2,6-C₆H₃-(i-Pr)₂) (1.04g, 3.47 mmol, 1.10 equiv) were dissolved together in ˜40 mL of Et₂O. Thereaction mixture was stirred overnight and then filtered through a fritwith Celite®. The Et₂O was removed in vacuo, and the product mixture wasdissolved in pentane. The pentane solution was filtered and then thesolvent was removed in vacuo to obtain 1.4 g (85%) of (Ia) as a yellowpowder: ¹H NMR (THF-d₈, 500 MHz, 25° C.) δ 8.15 (d, 2, H_(Ph)),7.56-7.44 (m, 3, H_(Ph)), 7.07 (d, 2, H_(aryl)), 6.99 (d, 2, H_(aryl)),6.97 (t, 1, H_(aryl)), 6.84 (t, 1, H_(aryl)), 2.98 and 2.46 (septet, 2each, CHMe₂ and C′HMe₂), 2.30 and 1.11 (s, 3 each, N═C(Me)—C′ (Me)═N),1.16, 1.14, 1.08 and 1.05 (d, 6 each, CHMeMe′ and C′HMeMe′). Thestructure of this compound was confirmed by X-ray crystal structureanalysis.

EXAMPLE 6 Ligand (Ib)

In a nitrogen-filled drybox, ArN═C(Me)—C(Me)═N—ONa (Ar=2,6-C₆H₃-(i-Pr)₂)(0.833 g, 2.95 mmol) and ArN═C(Cl) (Ph) (Ar=2,6-C₆H₃—Me₂) (0.724 g, 2.97mmol, 1.01 equiv) were dissolved together in ˜40 mL of Et₂O. Thereaction mixture was stirred overnight and then filtered through a fritwith Celite®. The Et₂O was removed in vacuo, and the product mixture wasdissolved in pentane. The pentane solution was filtered and then thesolvent was removed in vacuo. Next the product was dissolved in benzeneand filtered through basic alumina. The benzene was removed in vacuo toyield 0.841 g (61%) of (Ib): ¹H NMR (C₆D₆, 500 MHz, 25° C.) δ 8.37 (brm, 2, H_(aryl)) 7.35-7.16 (m, 3, H_(aryl)), 7.05 (d, 2, H_(Ph)) 6.93 (t,1, H_(Ph)), 2.68 (septet, 2, ChMe₂), 2.33 (s, 3, N═C(Me)—C′ (Me)═N),2.31 (s, 6, Ar: Me), 1.42 (br s, 3, N═C(Me)—C′ (Me)═N), 1.23 and 1.21(d, 6 each, CHMeMe′).

EXAMPLE 7 Ligand (Ic)

In a nitrogen-filled drybox, ArN═C(Me)—C(Me)═N—ONa (Ar=2,6-C₆H₃-(i-Pr)₂)(0.218 g, 0.772 mmol) and ArN═C(Cl) (Me) (Ar=2,6-C₆H₃-(i-Pr)₂) (0.186 g,0.782 mmol, 1.01 equiv) were dissolved together in ˜40 mL of a 1:3mixture of THF and pentane. The reaction mixture was stirred overnightand then the solvent was removed in vacuo. The product mixture wasdissolved in pentane and the resulting solution was filtered through afrit with Celite®. The pentane was removed in vacuo to yield (Ic): ¹HNMR (C₆D₆, 400 MHz, 75° C.) δ 7.13-7.01 (m, 6, H_(aryl)), 3.14 (septet,2, CHMe₂), 2.59 (septet, 2, C′HMe₂), 2.13 and 1.80 (br s, 6 and 3 each,N═C(Me)—C′ (Me)═N and 0C(Me)═N), 1.21, 1.07 and 1.06 (d; 12, 6 and 6each; CHMeMe′ and C′HMeMe′).

EXAMPLE 8 Ligand (Id)

In a nitrogen-filled drybox, a solution of ArN═C(Cl) (Me)(Ar=2,6-C₆H₃—Me₂) (0.459 g, 2.53 mmol, 1.02 equiv) in 25 mL of Et₂O wasslowly added over a 30 min. period to a 25 mL Et₂O solution ofArN═C(Me)—C(Me)═N—ONa (Ar=2,6-C₆H₃-(i-Pr)₂) (0.699 g, 2.47 mmol). Thereaction mixture was stirred overnight, 150 mL of pentane was added, andthe resulting solution was filtered through a frit with Celite®. Thesolvent was removed in vacuo, and the product mixture was dissolved inbenzene. The benzene solution was filtered through basic alumina andthen the solvent was removed in vacuo to yield (Id): ¹H NMR (C₆D₆, 500MHz, 25° C.) δ 7.27-6.73 (m, 6, H_(aryl)), 2.75-2.48 (br septets, 2,CHMe₂), 2.42-2.02, 1.95 and 1.71 (br singlets; 9, 3 and 3 each;N═C(Me)—C′ (Me)═N, Ar: Me₂, and OC(Me)═N), 1.08 (br resonance with asharp doublet superimposed, 12, CHMeMe′).

EXAMPLE 9 Ligand (Ie)

In a nitrogen-filled drybox, ArN═C(Me)—C(Me)═N—ONa (Ar=2,6-C₆H₃-(i-Pr)₂)(0.827 g, 2.93 mmol) and ArN═C(Cl) (t-Bu) (Ar=2-C₆H₄—Me) (0.612 g, 2.92mmol, 1.00 equiv) were dissolved together in ˜40 mL of Et₂O. Thereaction mixture was stirred overnight and then filtered through a fritwith Celite® to yield 0.917 g of (Ie) as a pale orange oil: ¹H NMR(THF-d₈, 500 MHz, 25° C.) δ 7.07-7.02 (m, 2, H_(aryl)), 6.98-6.87 (m, 3,H_(aryl)), 6.69 (t, 1, H_(aryl)), 6.55 (d, 1, H_(aryl)), 2.42 (septet,2, CHMe₂), 2.17 and 2.08 (s, 3 each, N═C(Me)C′ (Me)═N and Ar: Me), 1.40(s, 9, CMe₃), 1.12 (s, 3, N═C(Me)—C′ (Me)═N), 1.06 and 1.03 (d, 6 each,CHMeMe′).

EXAMPLE 10 Ligand (IIa)

Diethylenetriamine (2.272 g, 22.02 mmol) and 9-anthraldehyde (9.538 g,46.25 mmol, 2.10 equiv) were dissolved in methanol along with 10 dropsof formic acid. Within 15 minutes of mixing, a precipitate formed. Thereaction mixture was stirred overnight, and then the precipitate wascollected on a frit, washed with methanol and dissolved in CH₂Cl₂. TheCH₂Cl₂ solution was stirred overnight over sodium sulfate and thenfiltered through a frit with Celite®. The solvent was removed and theresulting orange powder (9.248 g, 87.56%) was dried in vacuo. The ¹H NMRspectrum is consistent with the isolation of (IIa) (˜90%) along withsmall amounts of by-products including 9-anthraldehyde and themono-imine intermediate: ¹H NMR (CDCl₃, 500 MHz) δ 9.46 (s, 2, N═CH orH_(aryl)), 8.47 (m, 4, H_(aryl)), 8.39 (s, 2, N═CH or H_(aryl)), 7.92(m, 4, H_(aryl)), 7.38 (m, 8, H_(aryl)), 4.11 (t, 4, NCH₂CH₂N′), 3.30(t, 4, NCH₂CH₂N′) 2.07 (br s, 1, NH).

EXAMPLES 11-20 General Procedure for the Synthesis of CoCl₂ and FeCl₂Complexes

In a nitrogen-filled drybox, a mixture of the ligand and MCl₂ (M═Co orFe) in ˜5 mL of THF was stirred for one to several days. The THFsolution was then filtered through a frit with Celite® and the solventwas removed in vacuo. Next, the solid was dissolved in toluene and theresulting solution was filtered through a frit with Celite®. The toluenewas evaporated and the resulting powder was washed with pentane anddried in vacuo.

EXAMPLE 11 (Ia)COCl₂

The above general procedure was followed using 630 mg (1.20 mmol) of(Ia) and 183 mg (1.41 mmol, 1.2 equiv) of CoCl₂ with the modificationthat following the evaporation of the THF, the product was dissolved ina 1:4 mixture of Et₂O/pentane and recrystallized to give 180 mg of aturquoise solid. The Et₂O/pentane was evaporated and the resulting solidwas dissolved in toluene. The resulting solution was filtered and thesolvent was removed to yield 97 mg of a light green solid (total yield:35.7%).

EXAMPLE 12 (Ia)FeCl₂

The above general procedure was followed using 650 mg (1.24 mmol) of(Ia) and 164 mg (1.29 mmol, 1.04 equiv) of FeCl₂. A brown powder wasisolated (582 mg, 72.1%).

EXAMPLE 13 (Ib)CoCl₂

The above general procedure was followed using 231 mg (0.494 mmol) of(Ib) and 62 mg (0.478 mmol, 0.968 equiv) of CoCl₂. A toluene-insolublefraction (bright green powder, 125 mg, 43.8%) and toluene-solublefraction (pale green powder, 10 mg, 3.50%) were isolated.

EXAMPLE 14 (Ib)FeCl₂

The above general procedure was followed using 278 mg (0.594 mmol) of(Ib) and 76 mg (0.60 mmol, 1.0 equiv) of FeCl₂. A toluene-soluble (brownpowder, 170 mg, 48.1%) and toluene-insoluble (brown powder, 28 mg,7.93%) fraction were isolated.

EXAMPLE 15 (Id)CoCl₂

The above general procedure was followed using 206 mg (0.508 mmol) of(Id) and 67 mg (0.52 mmol, 1.0 equiv) of CoCl₂. A moss green powder wasisolated (105 mg, 38.6%).

EXAMPLE 16 (Id)FeCl₂

The above general procedure was followed using 244 mg (0.602 mmol) of(Id) and 82 mg (0.65 mmol, 1.1 equiv) of FeCl₂. A light red-tan powderwas isolated (88 mg, 27.5%).

EXAMPLE 17 (Ie)CoCl₂

The above general procedure was followed using 138 mg (0.318 mmol) of(Id) and 47.1 mg (0.363 mmol, 1.10 equiv) of CoCl₂ with the exceptionthat following the evaporation of THF, the solid was not dissolved intoluene. Instead it was washed with pentane to give a green solid.

EXAMPLE 18 (Ie)FeCl₂

The above general procedure was followed using 95.5 mg (0.220 mmol) of(Ie) and 27.7 mg (0.219 mmol, 0.995 equiv) of FeCl₂ with the exceptionthat following the evaporation of THF, the solid was not dissolved intoluene. Instead it was washed with pentane to give a brown solid.

EXAMPLE 19 (IIIa)CoCl₂

The above general procedure was followed using 1.0095 g (2.105 mmol) of(IIIa) and 0.2576 g (1.984 mmol, 0.94 equiv) of CoCl₂, and 20 mL of THFwith the exception that the product was not soluble in THF. The tanprecipitate was washed with THF, toluene and pentane and then dried invacuo to yield 1.155 g (95.56%) of product.

EXAMPLE 20 (IIIa)FeCl₂

The above general procedure was followed using 1.0491 g (2.187 mmol) of(IIIa) and 0.2634 g (2.078 mmol, 0.95 equiv) of FeCl₂, and 20 mL of THFwith the exception that the product was not soluble in THF. Thered-orange precipitate was washed with THF, toluene and pentane and thendried in vacuo to yield 1.1583 g (91.92%) of product.

General Procedure for Ethylene Polymerizations and Copolymerizations forTables 1-4

Procedure. A 30 mL glass vial equipped with a gas inlet and fitted glasscap was dried in the oven. Upon removal from the oven, the gas inlet ofthe vial was sealed with electrical tape and the vial was immediatelypumped into a nitrogen-filled drybox. In the drybox, the glass vial wasloaded with a cobalt or iron compound. Next, solvent was added to theglass vial and the vial was cooled in the drybox freezer to −30° C. Thevial was briefly removed from the freezer while MMAO cocatalyst (1.7molar in Al, heptane solution) and optionally comonomer was added andthen placed back in the freezer to cool again. The cold vial was removedfrom the freezer, the top ground glass opening of the vial was greasedand capped, and the vial was removed from the drybox. The vial wasplaced in a plastic bag and the bag was cooled in dry ice until the vialwas loaded into a pressure tube and placed under ethylene; theelectrical tape covering the gas inlet was removed immediately prior tothis step. After the pressure tube was shaken mechanically for thestated reaction time, the ethylene pressure was released and the glassvial was removed from the pressure tube. The polymer was precipitated bythe addition of MeOH (˜20 mL) and concentrated HCl (˜1-3 mL). Thepolymer was then collected on a frit and rinsed with MeOH. The polymerwas transferred to a pre-weighed vial and dried under vacuum overnight.The polymer yield and characterization were then obtained. The followingabbreviations are used in the Tables: TO: number of turnovers per metalcenter=(moles ethylene consumed, as determined by the weight of theisolated polymer or oligomers) divided by (moles catalyst); M.W.:Molecular weight of the polymer or oligomers as determined by melt index(MI: g/10 min at 190° C., 2160 g weight), GPC (molecular weights arereported versus polystyrene standards; conditions: Waters 150° C.,trichlorobenzene at 150° C., Shodex® columns at −806 MS 4G 734/602005,RI detector), and/or ¹H NMR (olefin end group analysis); Total Me: Totalnumber of methyl groups per 1000 methylene groups as determined by ¹HNMR analysis.

In all of the Tables that follow “toluene-soluble” means that part ofthe transition metal compound that was soluble in toluene, whiletoluene-insoluble means that part of the transition metal compound whichwas insoluble in toluene. It is likely these fractions are the samecompound, with the solubility of the compound in toluene not being highenough to dissolve all the transition metal compound present.

TABLE 1 Ethylene Polymerization (5.9 MPa, p-Xylene (6 mL), 0.02 mmolCmpd, 18 h, 1 mL MMAO) Temp Ex. Cmpd (° C.) PE (g) PE (TO) 21 (Ie)FeCl₂25 0.316 458 22 (Ie)CoCl₂ 25 0.309 549

TABLE 2 Ethylene Polymerization (6.9 MPa, 1,2,4-Trichlorobenzene (8 mL),0.02 mmol Cmpd, 18 h, 2 mL MMAO) Temp PE M.W. (MI, GPC, Total Ex. Cmpd(° C.) PE (g) (TO) and/or ¹H NMR) Me 23 (Ia)FeCl₂ 25 5.493 9,580 MI <0.01; M_(n)(¹H): 0.7 no olefins 24 (Ia)CoCl₂ 25 0.11 188 25 (Ib)FeCl₂^(b) 25 6.77 10,900 MI < 0.01; M_(n)(¹H): 1.2 41,800 26 (Ib)FeCl₂ ^(c)25 10.79 17,700 MI < 0.01; M_(n)(¹H): 1.2 no olefins 27 (Ib)CoCl₂ ^(b)25 0.024 37.6 28 (Ib)CoCl₂ ^(a) 25 1.974 3,390 MI < 0.01; M_(n)(¹H): 8.87,110 29 (Id)FeCl₂ 25 13.11 18,700 MI < 0.01; M_(n)(¹H): 1.0 no olefins30 (Id)CoCl₂ 25 1.819 3,160 MI < 0.01; M_(n)(¹H): 13.2 2,650 31(Ie)FeCl₂ 25 3.161 5,400 MI < 0.01; M_(n)(¹H): 1.2 23,300 32 (Ie5)CoCl₂^(a) 25 0.363 2,430 M_(n)(¹H): 4,770 14.6 33 (IIIa)FeCl₂ 25 0.293 491M_(n)(¹H): 2,770 11.8 34 (IIIa)CoCl₂ 25 0.223 376 M_(n)(¹H): 6,560 4.8^(a)0.0053 mmol of cmpd were used. ^(b)Toluene-insoluble fraction.^(c)Toluene-soluble fraction.

TABLE 3 Ethylene Polymerization (1.0 MPa, 1,2,4-Trichlorobenzene (8 mL),0.02 mmol Cmpd, 18 h, 2 mL MMAO) Temp PE M.W. (MI, GPC, Total Ex. Cmpd(° C.) PE (g) (TO) and/or ¹H NMR) Me 35 (Ia)FeCl₂ 25 3.248 5,460 MI <0.01; M_(n)(¹H): 1.5 25,600 36 (Ia)FeCl₂ 60 0.666 1,140 MI < 0.01;M_(n)(¹H): 2.2 14,100 37 (Ia)CoCl₂ 25 0.035 60.0 38 (Ia)CoCl₂ 60 0.04060.9 39 (Ib)FeCl₂ ^(a) 25 3.21 5,580 MI < 0.01; M_(n)(¹H): 2.7 14,000 40(Ib)FeCl₂ ^(a) 60 0.742 1,290 MI < 0.01; M_(n)(¹H): 2.8 8,200 41(Id)FeCl₂ 25 4.359 7,390 MI < 0.01; M_(n)(¹H): 1.7 33,500 42 (Id)FeCl₂60 1.174 2,000 MI < 0.01; M_(n)(¹H): 2.1 24,400 43 (Id)CoCl₂ 25 0.8341,420 MI < 0.01; M_(n)(¹H): 12.0 4,840 44 (Id)CoCl₂ 60 0.398 672M_(n)(¹H): 3,590 11.2 ^(a)Toluene-soluble fraction.

TABLE 4 Ethylene/1-Hexene (1-H) Copolymerization (1.0 MPa,1,2,4-Trichlorobenzene (TCB), 0.02 mmol Cmpd, 18 h, 25° C., 2 mL MMAO)TCB 1-H Ex. Cmpd (mL) (mL) Polymer (g) 45 (Ia)FeCl₂ 4 4 0.758 46(Ib)FeCl₂ ^(a) 4 4 0.620 47 (Id)CoCl₂ ^(a) 4 4 0.289 48 (Id)FeCl₂ 4 40.846 49 (Id)FeCl₂ 7 1 1.134 50 (Id)FeCl₂ 0 8 0.581 ^(a)Toluene-solublefraction.

What is claimed is:
 1. A process for the production of polyethylene,comprising the step of contacting, at a temperature of about −100° C. toabout +200° C., a monomer component comprising ethylene, and an Fe or Cocomplex of a ligand of the formula:

wherein: R¹, R² and R³ are each independently hydrogen, hydrocarbyl,substituted hydrocarbyl or a functional group, or R¹ and R² takentogether may form a ring; Ar¹ and Ar² are each independently aryl orsubstituted aryl; R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ are eachindependently hydrogen, hydrocarbyl, substituted hydrocarbyl, or afunctional group, provided that any two of R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰and R¹¹ that are vicinal to one another may form a ring; R¹⁴ ishydrogen, hydrocarbyl or substituted hydrocarbyl; and Ar³ and Ar⁴ areeach independently aryl or substituted aryl.
 2. A process for theproduction of polyethylene, comprising the step of contacting, at atemperature of about −100° C. to about +200° C., a monomer componentcomprising ethylene, a compound of the formula:

and: (a) a first compound W, which is a neutral Lewis acid capable ofabstracting X⁻, an alkyl group or a hydride group from M to form WX⁻,(WR²⁰)⁻ or WH⁻, and which is also capable of transferring an alkyl groupor a hydride to M, provided that WX⁻ is a weakly coordinating anion; or(b) a combination of second compound which is capable of transferring analkyl or hydride group to M and a third compound which is a neutralLewis acid which is capable of abstracting X⁻, a hydride or an alkylgroup from M to form a weakly coordinating anion; wherein: M is Fe orCo; each X is an anion; n is an integer so that the total number ofnegative charges on said anion or anions is equal to the oxidation stateof M; R¹, R² and R³ are each independently hydrogen, hydrocarbyl,substituted hydrocarbyl or a functional group, or R¹ and R² takentogether may form a ring; Ar¹ and Ar² are each independently aryl orsubstituted aryl; R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ are eachindependently hydrogen, hydrocarbyl, substituted hydrocarbyl, or afunctional group, provided that any two of R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰and R¹¹ that are vicinal to one another may form a ring; R¹⁴ ishydrogen, hydrocarbyl or substituted hydrocarbyl; Ar³ and Ar⁴ are eachindependently aryl or substituted aryl; and R²⁰ is alkyl.
 3. A processfor the production of polyethylene, comprising the step of contacting,at a temperature of about −100° C. to about +200° C., a monomercomponent comprising ethylene, and a compound of the formula:

wherein: M is Fe or Co; R¹, R² and R³ are each independently hydrogen,hydrocarbyl, substituted hydrocarbyl or a functional group, or R¹ and R²taken together may form a ring; Ar¹ and Ar² are each independently arylor substituted aryl; R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ areeach independently hydrogen, hydrocarbyl, substituted hydrocarbyl, or afunctional group, provided that any two of R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰and R¹¹ that are vicinal to one another may form a ring; R¹⁴ ishydrogen, hydrocarbyl or substituted hydrocarbyl; Ar³ and Ar⁴ are eachindependently aryl or substituted aryl; Z¹ is hydride, alkyl or ananionic ligand into which ethylene can insert; Y is a neutral ligandcapable of being displaced by ethylene, or a vacant coordination site; Qis a relatively non-coordinating anion; P is a divalent polyethylenegroup containing one or more ethylene units; and Z² is an end group. 4.The process as recited in claim 1, 2 or 3 wherein R¹ and R² are eachindependently hydrogen or alkyl containing 1 to 4 carbon atoms or R¹ andR² taken together are:

R³ is aryl, substituted aryl or alkyl; Ar¹ and Ar² are 2-substitutedwith no substitution in the 6 position or 2,6-disubstituted phenyl, bothwith substitution optional at any other ring position; R⁴, R⁵, R⁶, R⁷,R⁸, R⁹, R¹⁰, R¹¹, R¹² and R¹³ are each hydrogen; R¹⁴ is hydrogen orhydrocarbyl and Ar³ and Ar⁴ are 9-anthracenyl.
 5. The process as recitedin claim 4 wherein: both R¹ and R² are hydrogen or methyl; R³ is aryl,substituted aryl or alkyl containing 1 to 4 carbon atoms; and R¹⁴ ismethyl or hydrogen.
 6. The process as recited in claim 1, 2 or 3wherein: (a) Ar¹ and Ar² are 2,6-diisopropylphenyl; R¹ and R² aremethyl; and R³ is phenyl; or (b) Ar¹ is 2,6-diisopropylphenyl; Ar² is2,6-dimethylphenyl; R¹ and R² are methyl; and R³ is phenyl; or (c) Ar¹and Ar² are 2,6-diisopropylphenyl; R¹ and R² are methyl; and R³ ismethyl; or (d) Ar¹ is 2,6-diisopropylphenyl; Ar² is 2,6-dimethylphenyl;R¹ and R² are methyl; and R³ is methyl; or (e) Ar¹ is2,6-diisopropylphenyl; Ar² is 2-methylphenyl; R¹ and R² are methyl; andR³ is t-butyl; or (f) R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹ R¹², R¹³ and R¹⁴are hydrogen; and Ar³ and Ar⁴ are 9-anthracenyl.
 7. The process asrecited in claim 1, 2 or 3 wherein a linear α-olefin is produced.
 8. Theprocess as recited in claim 1, 2 or 3 wherein the polyethylene ishomopolyethylene.